Cordless window blind structure

ABSTRACT

A cordless window blind structure comprises a head rail having an accommodating channel into which a cord-winding control device with an operational cord attached thereto and a fixed seat are mounted at both end sides with a movable seat situated there-between. The operational cord is also fixed to one side of the movable seat. Multiple lift cords mounted to the corresponding positions of a blind body and a bottom rail are guided into the accommodating channel and divided to extend from either the upper or lower side of a guiding post of the fixed and movable seats respectively and wind onto multiple guiding elements, permitting the operational cord to link in movement to the lift cords wound onto the movable and fixed seats. Therefore, the bottom rail is simply pushed or pulled by hands to easily and accurately adjust the blind body into a desirable collected or expanded position thereby.

BACKGROUND OF THE INVENTION

The present invention relates to a cordless window blind structure, comprising a head rail having an accommodating channel into which a cord-winding control device with an operational cord attached thereto and a fixed seat are mounted at both ends with a movable seat situated there-between wherein the operational cord is correspondingly linked in movement to lifts cords so that a bottom rail is simply pushed or pulled by hands to loosen or tighten the lift cords wound on the movable seat and synchronically actuate the operational cord therewith, facilitating easier and simpler adjustment of a blind body into a desirable collected or expanded position.

Conventional window blinds usually have pull cords mounted to suspend at one side of a blind body and retained in position by a pulley assembly to collect or expand the blind body thereby. In operation, the pull cords are drawn by force of hands to adjust the position of the blind body. Due to the small frictional surface thereof, the pull cords tend to rub against the hands or even abrade the hands directly contacting with them in an uncomfortable way if the pull cords are drawn to slide too fast. Furthermore, the pull cords are retained in place by the pulley assembly and are subjected to bear the total weight of the blind body. Thus, great efforts must be spent to draw the pull cords in operation, and the pull cords can easily get stuck in the pulley assembly, resulting in an awkward operation and becoming unsuitable for users of younger ages. Besides, in case of an excessive down-pulling force exerted onto the pull cords or a sudden release of the pull cords at great speed, the blind body cannot be accurately positioned in a desirable position and the adjustment process must be repeated over again, which is quite inconvenient in operation.

SUMMARY OF THE PRESENT INVENTION

It is, therefore, the primary purpose of the present invention to provide a cordless window blind structure wherein an operational cord attached to a cord-winding control device is correspondingly linked in movement to lift cords wound onto a movable seat and a fixed seat so that a bottom rail is simply pushed or pulled by hands to freely adjust the height of a blind body in an easy manner without the hands abraded by the conventional pull cords, achieving the best state of application thereby.

It is, therefore, the second purpose of the present invention to provide a cordless window blind structure wherein the cord-winding control device is equipped with torsion springs whose elasticity permit the operational cord to precisely recoil and locate in place according to the pushing/pulling force applied by the hands onto the bottom rail and the lift cords, avoiding the inconvenience of re-adjustment found in the conventional pull cords above to achieve more accurate and easier operation as well as assembly thereby.

It is, therefore, the third purpose of the present invention to provide a cordless window blind structure wherein the movable seat and the fixed seat are respectively equipped with a winding groove for multiple guiding elements and a transverse-extending guiding post to mount thereon so that the lift cords can be separately divided to extend from either the upper or the lower side of the guiding posts and wind onto the guiding elements thereon respectively, achieving the purposes of separating and guiding each lift cord without them entangling with each other so that the blind body can be smoothly expanded and collected in operation thereby.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view of the present invention.

FIG. 2 is an assembled cross sectional view of the present invention.

FIG. 3 is a partially enlarged and cross sectional view of the present invention.

FIG. 4 is a diagram showing a blind body of the present invention expanded downwards in operation.

FIG. 5 is a diagram showing the blind body of the present invention collected upwards in operation.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Please refer to FIG. 1 showing an exploded perspective view of the present invention. The present invention relates to a cordless window blind structure, comprising a head rail 10, a blind body 20, a bottom rail 30, a cord-winding control device 40, a fixed seat 50, and a movable seat 60. The upper side of the head rail 10 is defined by an accommodating channel 11 with cord passages 12 disposed thereon, and both internal side walls of the accommodating channel 11 are disposed a pair of symmetrically-extending guide tracks 13 each having a positioning recess 131 cut thereon. The blind body 20 is fixed between the head rail 10 and the bottom rails 30 thereof, and two or more than two lift cords 14, 14′ are mounted to the corresponding locations of the blind body 20 and the bottom rail 30 thereon. One end of each lift cord 14, 14′ is guided to pass through the cord passage 12 of the head rail 10 while the other end thereof is fixed to the bottom rail 30 thereon. The cord-winding control device 40 is composed of a base 41, a top sheet 42, and a rotary seat 43 mounted between the base 41 and the top sheet 42. An operational cord 44 is attached to the rotary seat 43 at one end and wound thereon. The bottom surface of the rotary seat 43 has a smaller-diameter rotating shaft 431 protruding thereon, and both sides of the rotating shaft 431 have a torsion spring 45 attached thereto respectively so that, depending on the actuation of the operational cord 44 and the spinning direction of the rotary seat 43, the torsion springs 45 are allowed to wind or counter-wind along the rotating shaft 431 and elastically locate in place thereby. The top sheet 42 of the cord-winding control device 40 is integrally coiled downwards at one side to form a pair of pivoting holes 421 thereon for a sliding post 46 to extend there-through and locate in place thereby. The fixed seat 50 and the movable seat 60 are respectively equipped with a set of bottom and upper plates 51, 52, 61, 62 to form a winding groove 53, 63 there-between correspondingly. And both winding grooves 53, 63 have multiple guiding elements 54, 54′, 64, 64′ vertically extending at one side thereon wherein the guiding elements 54, 54′, 64, 64′, depending on the length of the lift cords 14, 14′ can be respectively set into two or more than two in number. The winding groove 53 of the fixed seat 50 also has a guide rod 55 and a positioning rod 56 with a recess 561 cut thereon disposed at the other lateral side thereon. And the other lateral side of the winding groove 63 of the movable seat 60 are respectively disposed a fixed rod 65 and multiple symmetrically-arranged and larger-diameter pulleys 66 each having a grooved path 661 cut thereon. Besides, both bottom plates 51, 61 thereof have a pair of symmetrically-extending supports 512, 612 disposed at the corresponding sides thereon wherein each support 512, 612 has a flexible clip recess 511, 611 defining thereon so as to securely hold a guiding post 57, 67 in place thereon. And the bottom plate 61 of the movable seat 60 also has multiple supporting legs 613 extending downwards at the underside thereon.

Please refer to FIG. 2 showing an assembled cross sectional view of the present invention (accompanied by FIG. 3). In assembly, the movable seat 60 is mounted to the head rail 10 from one side to mesh the grooved path 661 of the pulleys 66 precisely with the guide tracks 13 so that the movable seat 60 is allowed to slide in the accommodating channel 11 thereby. The fixed seat 50 and the cord-winding control device 40 are respectively mounted to both end sides of the accommodating channel 11 of the head rail 10, permitting the cord-winding control device 40 to precisely located into the positioning recesses 131 thereof. Then, the movable seat 60 is situated between the cord-winding control device 40 and the fixed seat 50, permitting the supporting legs 613 to abut against the accommodating channel 11 therein. The lift cords 14, 14′ are then guided along the bottom surface of the head rail 10 to extend synchronically towards the winding groove 53 of the fixed seat 50 and wind around one guiding element 54 before led to wind continuously back-and-forth in an S-shaped manner onto the other guiding elements 64, 54′, 64′ thereof in a sequence. Then, the lift cords 14, 14′ are synchronically guided to run on the guide rod 55 and the recess 561 of the positioning rod 56 before tied up at the ends to form a fixed end 141 thereby. And, the lift cords 14, 14′ are separately divided to extend and wind from either the upper or lower sides of the guiding posts 57, 67, achieving the purposes of separating and guiding each lift cord 14, 14′ so as to prevent them from entangled with each other in operation. Finally, the other end of the operational cord 44 attached to the cord-winding control device 40 at one end thereof is secured to the fixed rod 65 of the movable seat 60 so that the operational cord 44 and the lift cords 14, 14′ are correspondingly linked to each other in movement to actuate the movable seat 60 thereby, completing the assembly of the present invention.

In operation, when the blind body 20 (referring to FIG. 4) is to be expanded downwards, the bottom rail 30 is pulled downward by hands, and the lift cords 14, 14′ drawn by the bottom rail 30 at the bottommost ends thereof are allowed to separately run along either the upper or the lower side of the guiding posts 57, 67 of the fixed seat 50 and the movable seat 60 and slide over each guiding elements 54, 54′, 64, 64′ to release downwards through the cord passages 12 respectively. Meanwhile, the supporting legs 613 and the pulleys 66 of the movable seat 60 actuated by the lowering of the lift cords 14, 14′ will slide on the accommodating channel 11 and the guide tracks 13 respectively and move towards the fixed seat 50 thereof. Then, the operational cord 44 is synchronically drawn to run on the sliding post 46 and extend along with the movable seat 60 therewith. And, the rotary seat 43 of the cord-winding control device 40 is actuated by the operational cord 44 to spin to one side, and the two torsion springs 45 juxtaposed to augment the elasticity thereby will be affected by the pulling force to revolve in an opposite and S-shaped rotation with a constant torque naturally occurred to counter wind thereby. Then, the constant torque occurred works in a linear operation and the torque will not be altered due to the increase of the coils wound, reinforcing the strengthen of the blind body 20 affected by the pulling force to achieve efficient suspension thereby.

When the blind body 20 (referring to FIG. 5) is to be collected upwards, the bottom rail 20 is pushed upwards by the hands, and the counter-wound torsion springs 45 will be released to naturally recoil backwards, permitting the rotary seat 43 to spin towards the other side with a constant torque occurred at the same time. Then, the movable seat 60 freed from the pulling force of the loosened lift cords 14, 14′ is actuated by the recoiling force of the withdrawing operational cord 44 to slide towards the cord-winding control device 40 thereof. Meanwhile, the lift cords 14, 14′ are drawn by the sliding movement of the movable seat 60 to run along the guiding elements 54, 54′, 64, 64′ sequentially and retrieve upwards through the cord passages 12 so as to collect the blind body 20 thereby. Therefore, via the pushing and pulling forces exerted by the hands to cooperatively work with the cord-winding control device 40 to generate constant torques in linking operation thereof, the present invention can prevent the hands from getting abraded by the pull cords found in the conventional window blinds so that a user can freely adjust the blind body 20 into a desirable position. In addition, the movable seat 60 and the fixed seat 50 are respectively equipped with a winding groove 53, 63 for multiple guiding elements 54, 54′, 64, 64′ and a guide post 57, 67 mounted thereto so that the lift cords 14, 14′ can be accurately divided and precisely wound thereon to achieve separating and guiding purposes thereby. Thus, the blind body 20 can be easily and smoothly expanded and collected without the lift cords 14, 14′ being entangled to each other, achieving the best state of application thereby. 

1. A cordless window blind structure, comprising a head rail with an accommodating channel defining thereon wherein the bottom surface of the accommodating channel has multiple cord passages disposed thereon and both end sides thereof are respectively secured a cord-winding control device and a fixed seat; besides, a movable seat is mounted to situate between the cord-winding control device and the fixed seat and allowed to freely slide in the accommodating channel thereof; a blind body is attached to the underside of the head rail at one end edge and fixed to a bottom rail at the other end edge thereof; multiple lift cords are mounted to the corresponding positions of the blind body and the bottom rail, and are respectively guided to pass through the cord passages of the head rail; the fixed seat and the movable seat are respectively equipped with multiple guiding elements and a transverse-extending guiding post so that the lift cords can be separately divided to extend from either the upper or lower side of both guiding posts to wind onto the guiding elements of both fixed and movable seats thereof in a sequence, efficiently achieving separating and guiding purposes and preventing the lift cords from entangling with each other; in addition, an operational cord is attached to the cord-winding control device at one end and fixed to one side of the movable seat at the other end thereof so that the operational cord can be correspondingly linked in movement to the lift cords wound onto the movable seat and the fixed seat thereon; therefore, the bottom rail is simply pushed or pulled by hands to loosen or tighten the lift cords wound on the movable seat, and actuate the movement of the operational cord therewith to form a state of counterbalance there-between, permitting a user to easily and smoothly adjust the blind body into a desirable collected or expanded position thereby.
 2. The cordless window blind structure as claimed in claim 1 wherein the cord-winding control device is composed of a base, a top sheet, and a rotary seat that, mounted between the base and the top sheet, has an operational cord attached and wound thereto; the bottom surface of the rotary seat has a smaller-diameter rotating shaft protruding thereon, and both sides of the rotating shaft have a torsion spring mounted thereto respectively so that, depending on the actuation of the operational cord and the spinning direction of the rotary seat, the torsion springs are allowed to wind or counter-wind along the rotating shaft and elastically locate in place thereby.
 3. The cordless window blind structure as claimed in claim 2 wherein the top sheet of the cord-winding control device is integrally coiled downwards at one side to form a pair of pivoting holes thereon for a sliding post to extend there-through and locate in place thereby.
 4. The cordless window blind structure as claimed in claim 1 wherein the fixed seat and the movable seat are respectively equipped with a set of bottom and upper plates to form a winding groove there-between for the mounting of the guiding elements thereon; both bottom plates of the fixed and movable seats have a pair of symmetrically-arranged supports disposed at the corresponding sides thereon respectively, and each support has a flexible clip recess defining thereon so as to hold the transverse-extending guiding post firmly in place thereby.
 5. The cordless window blind structure as claimed in claim 1 wherein the number of the guiding elements of the fixed and the movable seats can be determined by the length of the lift cords and set into two or more than two thereof.
 6. The cordless window blind structure as claimed in claim 4 wherein the winding groove of the fixed seat has a guide rod and a positioning rod with a recess cut thereon disposed at one lateral side thereon, to which the lift cords are synchronically guided to run and wind thereon with the ends tied up to form a fixed end thereby.
 7. The cordless window blind structure as claimed in claim 4 wherein the winding groove of the movable seat has a fixed rod extending at one side thereon for the attachment of the operational cord thereto.
 8. The cordless window blind structure as claimed in claim 4 wherein the bottom plate of the movable seat also includes supporting legs extending downwards at the underside thereon.
 9. The cordless window blind structure as claimed in claim 1 wherein the movable seat and the head rail are respectively equipped with multiple pulleys each defined by a grooved path, and a set of guide tracks each defined by a positioning recess, permitting the pulleys of the movable seat to slide along the guide tracks of the head rail in operation. 